Peening apparatus



Nov. 29, 1949 B. F. FOWLER PEENING APPARATUS Original Filed May 2, 19464 Shets-Sheet 1 IN V EN TOR.

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Nov. 29, 1949 B. F. FOWLER PEENING APPARATUS 4 Sheets-Sheet 2 OriginalFiled May 2, 1946 INVENTOR. M

Wv M/I IVTTORA/EYS.

Nov. 29, 1949 B. F. FOWLER I PEENING APPARATUS 4 Shets-Shet 5 OriginalFiled May 2, 1946 INVENTORL @a/WW M' ATTORNEYS.

Nov. 29, 1949 B. F. FOWLER 2,439,377

PEENING APPARATUS Original Filed May 2, 1946 4 Sheets-Sheet 4 INVENT OR.

A BY

TTORNE YS.

Patented Nov. 29, 1949 The Studebaker Corporation, South Bend, 1nd, acorporation of Delaware Original application May 2, 1946, Serial No.666,773. Divided and this application February 9, 1948, Serial No. 7326111 Claims. (01. 51 -15) My present invention relates to an improve mentin peening apparatus of the type in which shot is caused to beprojectedupon metal articles to remove fissures or other imperfectionstherein and thereby materially increase the mechanical strength of thearticle.

My present application is a division of my on pending application SerialNo. 666,773 filed May 2, 1946 So far as I am aware most prior forms ofapparatu's of the above character usually comprises a centrifugal Wheelupon which shot is caused to be fed and which wheel is rotated at highspeed so that the shot is projected by centrifugal force withconsiderable force upon a metal article being peened.

These prior forms of apparatus are unsatisfac tory for several reasonsvPerhaps, the foremost disadvantage lies in the fact that it is diflicultto control Within narrow limits the desired peening of an article withthe shot. This difficulty is due to the inability to effect the controlin such apparatus of the amount of shot being projected upon an articlewith a predetermined amount of force so that the resultant peening ofthe article is not always uniform Further, such prior apparatus is onlyeffective to project shot in the plane or ro tation of the centrifugalWheel, and for irregular- 1y shaped articles is unsuitable in that onlythat part of the article caused to be passed through the plane ofrotation of the wheel is caused tob'e peened.

It is an object of my present invention to provide peening apparatushaving nozzle means through which shot is adapted to be dischargedcomprising Work supporting means of a character for subjectingsubstantially all portions of an article supported thereon to the shotdischarged through the nozzle means.

A further object of my invention is to provide peening apparatus havingnozzle means through which shot is adapted to be discharged comprisingwork supporting means for supporting an article to be peened, drivemeans for driving the work supporting means, and means under the controlof the driving means for controlling the delivery of shot and air underpressure to the nozzle means for discharge of the shot through thenozzle means upon the article to be peened.

A further object is to provide an apparatus as last aforesaid havingmeans for automaticany controlling the flow of shot and air u'r'iderpressure to the nozzle means for a predetermined length of time providing acycle of operation for the apparatus in the peening of articletherewith.

In order to accomplish the aforesaid objects, I;

propose to provide an apparatus having a work supporting member forsupporting an article to be peened. The apparatus further comprisesahopper or other suitable receptacle for support ing shot to be uses inthe eening operation, and

which shot through suitable valve means is adapted to be delivered to aconduit feeding into a nozzle means through which the shot is to bedischarged 111 3911 th'wfifik SliiJiJbltd the work supporting member;The nozzie means further is' adapted to have Gr-ihetlhii through aconduit with a source of air under pressure with air under I ressureflowing through the nozzle means being e-Iie'ctive to dischargetherefrom the shot being fed from the hopper to project the shot uponthe article. Thus the shot to be projected upon the article is aused tobe ueiiveredto the nozzle means, and the air under pressure is effectiveto cause the shot to be impinged upon the article with the force thereofbeing controllable by com predetermining the amount oi shot delivered touienozzie means.

The previousi'y referred to valve means con:

trolling delivery or shot to the conduit leading to the nozzle meanstogether with valve means nozzle means are caused to be automaticallyclosed upon the completion of a cycle of a predeconnecting the airpressure conduit with the termine'd length of time of treatment or anarticle with the shot. Upon completion or such cycle, the valve meansfor the shot and the air caused to be closed terminating thepredetermined period of shot blasting of the article.

In the preferred form or my invention the valve means oontroning thedelivery (if shot to the I nozzle means and the nozzle means areprovided with replaceable orifice members for controlling the amount ofshot adaptedto be delivered to the a nozzle means and the velocity ofair under pressure adapted to be delivered there through to com trol theamount and force with which the shot is 5 caused to be impinged upon anarticle being 1 treated;

The aboveand other objects-anti advantages of my invention Will appearfrom the detail de i scription.

Now, in order to acouamt those skilled in the j art With the manner ofconstructing and utilizing j apparatus in accordance with my invention,I

shall describe in connection wit the accomw 3 panying drawings apreferred embodiment of my invention.

In the drawings:

Figure 1 is a front elevational view of apparatus constructed inacordance with my invention with the upper housing portion of theapparatus being broken away to illustrate the supply hopper for the shotand associated parts;

Figure 2 is a side elevational view with certain parts being shown insection, and with the enclosing housing of the apparatus removed to showthe manner in which an article is adapted to be supported and rotatedwithin the shot blasting chamber of the apparatus of Figure 1;

Figure 3 is a plan view of the portion of the apparatus shown in Figure2;

Figure 4 is a detail vertical sectional view taken substantially on theline 44 of Figure 2 looking in the direction indicated by the arrowsillustrating timing cam means for controlling the cycle of operation ofthe apparatus;

Figure 5 is a detail vertical sectional View taken substantially on line5-5 of Figure 1, looking in the direction indicated by the arrows withcertain of the parts being broken away and shown in section forclearness of illustration;

Figure 6 is a plan view of a portion of the control means forcontrolling the flow of shot and air under pressure to nozzle means forprojecting the shot upon an article being treated; and

Figure 7 is a detail lengthwise sectional view through a preferred formof nozzle means of the apparatus of my invention.

Referring now to Figure 1,- the apparatus ll} of my invention comprisesa supporting platform ll formed of suitable structural steel framemembers for supporting a housing l2 which in the embodiment of myinvention herein disclosed comprises a pair of shot blasting chambersl6l 6, in which articles to be shot blasted or peened are caused to besupported upon a work supporting platform means i'l, shown in detail inFigures 2, 3 and 4, with each of the chambers It being adapted to beclosed at the front of the apparatus by doors Iii-i8 hingedly mounted asat It along opposite side edges of the front wall of the apparatus.Suitable known link locking mechanisms are associated with each of thedoors l8l8 and are operable through the handle members 2| for openingand closing the doors and through which the work to be shot peened isadapted to be disposed within the chambers l6l5. The doors l8 arefurther provided with windows 2| through which peening of the articlesmay be observed. 7

In the particular form of apparatus i2 shown in the drawings a pair ofchambers I6 are shown, and the description of my invention hereinafterwill be limited to the means associated with the chamber at the left ofFigure 1 for efiecting the shot peening of an article disposed therein,it being understood in the apparatus shown the parts hereinafterdescribed are duplicated for the other or right chamber of Figure 1 toprovide an apparatus in which two parts may be caused to be shot peenedby a single operator of the apparatus.

Referring now more particularly to Figures 2,

4 unit 24. The output shaft of the gear reduction unit has a pinionmeans suitably keyed thereto as by means of the intergral sleeve 25thereof having drive fitting engagement with the output shaft of thegear reduction unit 24. A pinion 21 at the outer end of the sleeveportion 26 has meshing engagement with a gear 28 carried by a shaft 33,the opposite ends of which are suitably journaled in ball bearingassemblies supported within a pair of brackets 32, 32 carried on ahorizontal extending frame or panel member 3!. A pinion means 33 is alsosuitably secured to the shaft and the teeth 34 integral therewith hasmeshing engagement with a gear 35 keyed to a shaft 36 which is journaledintermediate its ends inv a suitable bracket 31 and with the shaft 36 atits outer end being rotatably supported in a bracket 38 fixed to member31. The shaft 36 at its inner end has a cam 39 suitably keyed theretowith the inner end of the shaft 36 having connection with a shaft 40 bymeans of a keying member 4! of known construction. The inner end of theshaft 40 has a bevel gear 43 fixed thereto with the inner end of theshaft 49 being saitably supported and mounted for rotation in a gear boxhousing 44 of known construction. The bevel gear 43 is adapted to haveconstant meshing engagement with a bevel gear 45 fixed to one end of avertically extending shaft 48 which at its upper end is journaled in aball bearing assembly 58, the outer race of which is supported in theupper end of a sleeve portion 53 extending coaxially of the shaft 43 ofa supporting member 54, and which sleeve portion is enlarged to form aclosure plate portion 55 forming part of the gear housing 44 and inwhich a second ball bearing assembly 56 is provided for rotatablysupporting the shaft 48. The shaft 48 at its upper end is provided witha reduced end portion 51 adapted to fit in a socket formed in the worksupporting member I? with the work supporting member I? being furtherformed with an annular enclosing housing portion 58 into which the upperend of the sleeve portion 53 surro ending the shaft 48 projects andproviding a support for rotation of the work supporting member 11,together with the shaft 48 about the axis thereof. A cap member 69 isprovided with an annular sleeve portion 6| fitting over the reducedupper end 59 of the shaft and a nut 62 is adapted to have threadingengagement with the upper end of the shaft to secure the member inposition to support an article 63 to be treated in the chamber it of theapparatus. The article 63 as shown in the embodiment of the apparatus ofmy invention herein disclosed is an articulating rod which is adapted tobe secured in the position shown by the member 63 by the means describedand in which the radially projecting arm portion 54 of the worksupporting member I! is provided with a pair of upwardly projecting pins65) between which the outer end of the articulating rod is disposed sothat the articulating rod is caused to be rotated with the worksupporting member I! when the shaft 48 is rotated.

As shown more clearly in Figure 5 the collar or sleeve portion 53 ofsupporting member 54 is provided with a plate portion 10 secured alongopposite side edges thereof on a pair of spaced I- frame members 'H1Iextending lengthwise of and parallel of the axis of the shaft 43 andresting upon a panel 12 closing the lower end of the chamber l6 andtogether with suitable framing members supporting the several parts lastdescribed.

Quasar it'ef erringinow more particularly: .to Figures 2;; 3; and 4, itwill: be. observedzthat the cam member; 39: provided with asubstantially-g. V-shaped, notch13 extending inwardly at al-pcrtionof-the. circumference thereof, and; into which notchasroller I4. carriedby a pin fixed inanzear or lug 'I6 of alever "I5 is adapted to haveengagement The-lever 82 is pivoted tothe angleiron member 83 as at 85,and at 86 has pivotal=connectionz with a horizontally extending rod 81supported forhorizontal reciprocal movement in a blockv As shownmoreclearly in Figure 6, the rod 81 has connection at its other 88- (SeeFigure 6) endwith-anarm 88' secured to a vertically extending shaft 89supported in a collar member- 90 supported ona transversely extendingplate or-panel member 92 forming the upper end of the chamber I; Alever93 is connected-to the shaft 89 and has a link 94' pivoted at one endthereto and at its other end to a connecting joint 95 fixedto the valveactuating handle '96 of an air valve" 91-with a second link 98 extendingfromthe connection 95 to a c0nnect0r-99 fixed to -a valve actuatinghandle member I00 for a second-air valve I 02. A rod or link I03 haspivotal connection adjacent the outer end of-the arm 88' atone end andintermediate its ends has pivotal connection with'an arm I fixed toshaftI06-with a second arm I01 alsofixed to shaft 106 havingpivotalconnection at its other end with one end of alink I08, the otherend of which has pivotal connection at I09 with a valve H0 pivoted atits opposite end as at III. The other opposite end of connecting link orrod I03 has pivotal connection with a link II3 fixed to shaft H4 and towhichis also fixed a second link I I-5 having pivotal connection at itsouterend with one end of-a rod or link I I6, the opposite end of whichhas pivotal connection with one end of valve I I1 pivoted at itsother-end as at I I8. A third-arm H9 is also fixed to shaft I I4 and haspivotal connection at its outer end with'a first link or rod-- '9'having pivotalconnections as at I with a'valve I2I pivoted as at I22 andwith a rod or link' I23 extending from the pivotal-connectionof the linkI IS with the valve I22,- having pivotal connection with one end of avalve I24 and with t e other end of valve I24 being pivoted as at I25; 7

Thearrangement is such that upon rotation of the timing cam 39 theroller I4 is adapted to ride on'the periphery of the disk or cam element39 inwhich position the connecting rod 'or link 80 is urged upwardly andwhich movement of the rod 65 of-therod 81 to the right; as viewed inFigure 6, rotating the several arm members described in 'a afl throughthe lever member 82 effects movement clockwise direction as viewed "inthis figure, and

in -which position air under pressure is causedto be delivered from amanifold I through thepair of; valves Q-I'and I02; and with'the severalvalvemembers H9, H1, HIV and [Mr-being moved $01 open pcsitionthepurpose of whichwill be referredto hereinafter. It will be understoodthat" thexmanifold I 30- 1 has; suitable: connection .to: a-

781mg .orificermember' :I 63 in position in the nozzle source of: airunderpressure; I as -for example :a suitable air-compressor(not'showmfto provide for the flow of air under pressure through :the Ivalves Bland I02 forv apurDose-to be described. Uponvcontinuedrotationof the cam member 39 the roller 14 drops into the. vl-shapedinotch I3extending; inwardly of the periphery thereof whereupon the lever member15 is caused to I assume theposition shown in Figure 4, and inwhichgposition downward movement oflthei rod or link- 80 effectsclosingnoffthe air valves 91, I02 and the several valve membersIIU,II'I, I21, and I24tcclosed positiontby movement ofthe rod 81 to the r-lleft-as-shown in Figure 3 through the-linkageabove described.

Referring now more particularly to Figure 5,

it will besobserved that a hopper I40 is disposed* at'the'upper end oftheframe of the apparatus: and is adapted to contain theshot-usedforpeen- I ingof the articulating rod 63 supported on the work:supporting member I1.

The hopper I40 has disposed-in thelower bottom wall thereof a plurality.of discharge metering members I42 mounted in brackets I43 suitably"secured thereto and at-the lower ends one each of which thevalve-members II 0, H1, I2I' and I24; previously described, aredisposed'below the discharge ends of .the bores I44 which are'adaptedtobe opened and-closed by-these several valve members, and

which valve members'in their open position as when the roller I4 isengaged with the outer pe-' ripheral surface of-the timing cam member'39 are in their open position so that shot is adapted tobe'dischargedtherethrough into the funne1-- shaped members I45 disposedtherebelow.- The funnel members I45 extend into the open upper ends of aplurality of conduits I46-of rubber or other suitable flexible material,and which at their outer ends aresupported in metal sleeve members llsuitably secured in the annular brackets I50 securedto the upper surfaceof the transversely extending panel member 92' enclosing-the upper endof-chamber I6. The conduits I46'eachextend to a nozzle I5|','shown indetail .inFigure 7. Also, as shown-in Figure 5, a pluv rality of a airhoses I53, extend from air'valves such as the air valves 91 and I02,previously described, with each of-the air conduits also ex-' tending toone ofthe nozzle means I5I. In the embodiment disclosed each of the airvalves 91 r and l02'have connection with a pair of conduits I53 one ofwhich extends to a nozzle I5I. Suitable angle bracket'means indicatedgenerally at I55 provides for the support of the several nozzles I5I-ofwhich there are four in the embodiment of the apparatus disclosed, intheposition shown in Figure 5, and in a position to direct shot uponthearticulating rod 63 'for peening the latter;

The supporting "bracket means further provides. 1 for adjusting thepositions of the nozzles within the chamber l6.

Referring now more particularly to Figure 7; it willbe observed that theshot supply conduit I46 in the nozzle shown is secured in an annularsleeve-portion I 51 formed integrally of nozzle housing member I58 withthe housing I58 being v formed with a bore I59 in alignment with'thebore of the conduit I46. An air conduit I53 also has connection with atubular metal sleeve I60 A lock screw. I provides forsecuring the'meter"which, as shown in Figure 7, is-provided with an enlarged "end portionI62 having threaded en--- gagement with a metering orifice member I63fitting in-ta bore I64: in the nozzle housing I58-.

7 housing I58. The nozzle housing member I58 is provided with acylindrical member I65 having threaded engagement with a'tappedcounterbore I1I' extending coaxially of a bore I66 intersecting the boreI59. An annularwasher I61 is disposed adjacent and seats upon a shoulderformed at the outer end of the bore I66 and is secured in position bymeans of the aforesaid threaded engagement of member 165' with thenozzle housing. A sleeve member I13 is disposed withinthe member I65 andis retained therein by the turned in outer end of the sleeve I65. Thesleeve I13 is provided with a discharge bore I14 which, at its innerend, is provided witha funnel shaped portion I15 maintained in alignmentwitha circular opening or passage I11 formed in the washer I61 and intowhich the outer projecting end of the reduced cylindrical portion I18 ofthe metering element I63 projects. A resilient nozzle member I86 fitsover the sleeve member I65 and at its inner end over the projecting endof the housing I58 at the counterbore I1I thereof receiving the memberI65 and at its outer end is provided with a flared opening I 82 throughwhich the shot is caused to be projected upon the articulating rod 63shown in the work supporting member I1. It will be observed upon airunder pressure being admitted to the several conduits I53 to ,each ofthe nozzles I5I that the shot being fed through the conduits I 46 intothe bores I59 and the intersecting bore I66 that it is caused by the airbeing discharged through the reduced portion of the metering orificemembers I63 to be discharged through the bores I14 of the members I13upon the articulating rod 63.

The shot being discharged through the nozzle means I5I may be controlledby the provision of adesired metering member I44 at the lower ends ofthe hopper for eifecting a predetermined rate of flow of shot into theseveral conduits I46 and together with the incorporation of the nozzlemeans I5I of an orifice member I63 providing for the delivery of airunder pressure at a predetermined velocity to effect the dischargethrough the nozzle means of the combined air and shot through the boreI14 of the member I13 I to provide for the peening of the articulatingrod- 63 with a predetermined amount of shot and propelled at apredetermined force.v The screw 65 provides for the ready substitutionof metering orifice member I63, as desired, and the metering orificesI44 at the lower ends of the hopper are suitably carried in thedetachable supporting bracket members I43 to provide for thesubstitution thereof to provide for a predetermined delivery of shotinto the conduits I46.

It is believed that from the above description of the embodiment of anapparatus constructed in accordance with my invention that the operationthereof will be readily understood. However, briefly, it will be seenthat with the apparatus disposed in the position .of the timing cam 39shown in the drawings that the air valves such as that shown at 91 andI82 for the vdischarge nozzle member means I5I, and together with the 7valve members for the shot discharge metering elements M2 associatedwith the chopper con- 5 taining the shot in closed position that thedoor I 8 may be opened and an articulating rod or; other article to betreated suitably assembledupon the work supporting member I1. After the'r': article to be treated has been arranged on the. work supportingmember the door I8 to the se- I lected chamber I6 is closed and atripping switch (notshown) is actuated to cause theelectricmois beingrotated within the chamber I6 with theshot being projected inpredetermined amount and with predetermined force upon the articulatingrod 63. Preferably, the gear ratios between the pair of bevel gears 43and 45 and the cam member 39 are such that upon one rotation of the cammember 39 the work supporting member is caused to be rotated once, ormore if desired, and when the cam member reaches the position shown inFigure 3 the roller 13 drops into the V-shaped notch 14 shutting off thesupply of air under pressure to the several nozzles I5I and of shot tothe conduits I46 leading to the nozzles I51. As

shown in Figure 4 the cam 39 has a switch actuating member I96associated therewith and which is adapted to trip a switch I9I to stopthe electric motor 23 and thus completing one cycle of operation for theapparatus so that the door I8 may now be opened and the treated articleremoved and another article to be treated arranged upon the worksupporting member I1. The lower end of the apparatus is provided with asuitable collector pan I85 for collecting the spent shot which afterbeing cleaned and graded is returned by suitable known means to thehopper. Also, as shown in Figure 5, a suitable conduit 186 to dustcollector has connection with the chambers I6. It will be understood aspreviously related that the mechanism is duplicated for the othercompartment I6 shown at the right of Figure 1, so that if desired asingle workman may cause the alternate operation of the shot blastingapparatus associated with each of the chambers so 'that, during theremoval and insertion of one article in one of the chambers an articlein the other of the chambers is undergoing shot peening.

I have above described the general nature and arrangement of anapparatus constructed in accordance with my invention, and it will beobserved that the several nozzles may be readily adjusted upon the angleiron supporting bracket means I 55 to provide for the arrangement of thenozzles with respect to the work to achieve the most advantageous shotpeening of the metal articles being treated. It will be understood thatI44 providing for the feeding of a predetermined amount of shot througha conduit leading to a discharge nozzle which has associated with it aconduit for directing air under pressure thereto,

and which-by means of the association therewith of; selected meteringorifice members I63 provides for the. discharge'from the nozzle of theshot ldelivered thereto with a predetermined amount of force to provide"for a predetermined peening of a metal article.

' Thus while I have shown'what I consider to be the preferred embodimentof my invention, it

" tion of work supporting means for rotatably supporting an article tobe peened, drive means for rotating said work supporting means, nozzle'-means for discharging shot upon said article,

means including first valve means for delivering shot to said nozzlemeans, means including second valve means for controlling flow of airunder pressure to said nozzle means to discharge the shot deliveredthereto by said last named means,

and said drive means including means for conjointly' controlling openingand closing of said first and second valve means.

2. Peening apparatus-comprising the combination of a rotatably mountedwork supporting member for supporting an article to be peened, drivemeans for rotating said work supporting member, nozzle means fordischarging shot upon the article adapted to be supported on said worksupporting member, a hopper for supporting a supply of shot, first valvemeans associated with said hopper and operable in its open position toefiect discharge of shot from said hopper, first conduit means forreceiving shot discharged through said first valve means and conductingthe same to said nozzle means, second conduit means for conducting airunder pressure to said nozzle means for discharging therefrom shotdelivered thereto through said first conduit means, second valve meansassociated with said second conduit means and operable for closing thesame to prevent flow of air under pressure therethrough, and cam meansassociated with said drive means and said first and second valve meansfor effecting conjointly opening and closing of said first and secondvalve means.

3. Peening apparatus comprising the combination of work supporting meansfor rotatably sup-' porting an article to be peened, drive means forrotating said work supporting means, including a shaft means having gearmeans between the latter and said rotatably mounted work supportingmember for rotating the latter, nozzle means for discharging shot uponthe article adapted to be supported on said work supporting member, ahopper for supporting a supply of shot, first valve means associatedwith said hopper and operable in its open position to effect dischargeof shot from said hopper, first conduit means for receiving shotdischarged through said first valve means and for conducting the same tosaid nozzle means, second conduit means for conducting air underpressure to said nozzle means for discharging shot delivered theretothrough said first conduit means, second valve means associated withsaid second conduit means and operable for closing the same to preventfiow of air under pressure therethrough, and means associated with saiddrive means and said first and second valve means including a cam memberrotatable with said shaft means for conjointly controlling opening andclosing of said first and second valve means in predetermined positionsof said work supporting member.

4. The combination of claim 3 characterized a 10 by said drive meansincluding said cam member beingadapted to effect closing of the firstand second valve means upon a single revolution of said work supportingmeans. 7

5. Peening apparatus comprising the combination of a rotatably mountedwork supporting member for supporting an artice to be peened,

driving means :including a shaft means having gear meansbetween thelatter and said rotatably mounted work supporting member for rotatingthe latter,nozzle means for discharging shot-upon the article adapted tobe supported on said work supporting member, a hopper for supporting --asupply. of; shot, first valve means associated with said hopper andoperable in its open position to effect-discharge of shot from saidhopper by gravity,,-first--conduit means forreceiving shot dischargedthrough said first valve means and for conducting the same by-gravitytosaid nozzle means, second conduit means for conducting airunder-pressure to said nozzlemeans for'discharging therefrom shotdelivered thereto through said first conduit means, second valve meansassociated with said secondconduit'means andxoperable for closing thesame to prevent flow Ofiflll under pressure therethrough, and meansassociated with said drive means and said first and second valve meansand including a cam member rotatable with said shaft means forconjointly controlling opening and closing of said first and secondvalve means in a predetermined position of said work supporting means.

6. Peening apparatus comprising supporting means for rotatablysupporting an article to be peened, means for rotating said supportingmeans, nozzle means for discharging shot upon the article adapted to besupported by said supporting means, means including first valve meansfor delivering shot to said nozzle means, means including second valvemeans for delivering air under pressure to said nozzle means, and meansassoci ated with said driving means for conjointly opening and closingsaid first and second valve means at a predetermined position of saidwork supporting means.

7. Peening apparatus comprising the combination of movable Worksupporting means, drive means for driving said work supporting means,nozzle means for discharging shot toward said work supporting means, a,hopper for supporting a supply of shot, valve means associated with saidhopper and operable for discharging shot from the latter at apredetermined rate, first conduit means for receiving shot dischargedthrough said valve means and conducting the same to said nozzle means,second valve means adapted to be associated with a source of air underpressure, second conduit means extending from said second valve means tosaid nozzle means for conducting air under pressure to the latter todischarge therefrom shot delivered through said first conduit means, andsaid drive means including means for conjointly opening and closing saidfirst and second valve means.

8. Peening apparatus comprising the combination of movable worksupporting means, drive means for drivin said work supporting means,nozzle mean-s for discharging shot toward said work supporting means,means including first valve means for delivering shot to said nozzlemeans, and means including second valve means for controlling flow ofair under pressure to said nozzle means to discharge the shot deliveredto said nozzle means by said first means, and said drive means includingmeans for conjointly cOntrolling, opening and closing of said first and1 second valve means. '9. Peening apparatus comprising the combinationof movable work supporting means, drive means for driving said worksupporting means,

noz zlemeans for discharging shot toward said work supporting means, ahopper for supporting a supply of shot, first valve means associated fordischarging therefrom shot delivered 'thereto "through said firstconduit/means, second valve means associated with saidsecond conduitmeans and operable for closing the same to prevent the iiow of air underpressure therethrough, and said 'drive' means including means forconjointly controlling opening and closing of said first and sec- "ondvalve means. 1

10. Peening apparatus comprising the combination of movable worksupporting means, drive means for driving said work supporting means,

nozzle means for discharging shot toward said work supporting means,means including first valve means for delivering shot by gravity to saidnozzle means, and means including second valve means for controlling thefiow of air under pressure to said nozzle means to discharge the shotdelivered to said nozzle means by said first means, and said drive meansincluding means for conjointly controlling opening and closing of saidfirst and second valve means.

l1. Peening apparatus comprising movable supporting means for supportingan article to be peened, drive means for driving said work supportingmeans, nozzle means for discharging shot upon said article, means fordelivering shot at a predetermined rate to said nozzle means, andmeansfor delivering air under pressure at a predetermined velocity tosaid nozzle means to discharge the shot delivered thereto with apredetermined force, and said drive means including means for conjointlypreventing fiow of shot and air under pressure to said nozzle means.

BERT F. FOWLER.

No references cited.

Certificate of Correction Patent N 0. 2,489,877 November 29, 1949 BERTF. FOWLER It is hereby certified that errors appear in the abovenumbered patent requiring correction as follows:

In the rant, line 1, address of inventor, for Vero Beach, California,read Vero Beach, Florzda; in the heading to the printed specification,line 3, for Vero Beach, Calif. read Vero Beach, Fla.;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Oflice.

Signed and sealed this 28th day of March, A. D. 1950.

THOMAS F. MURPHY,

Assistant Oommz'ssz'oner of Patents.

